git/hex.c

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#include "git-compat-util.h"
#include "hash.h"
#include "hex.h"
static int get_hash_hex_algop(const char *hex, unsigned char *hash,
const struct git_hash_algo *algop)
{
int i;
for (i = 0; i < algop->rawsz; i++) {
int val = hex2chr(hex);
if (val < 0)
return -1;
*hash++ = val;
hex += 2;
}
return 0;
}
hex: retire get_sha1_hex() The naming convention around get_sha1_hex() and its friends is awkward these days, after "struct object_id" was introduced. There are three public functions around this area: * get_sha1_hex() - use the implied the_hash_algo, fill uchar * * get_oid_hex() - use the implied the_hash_algo, fill oid * * get_oid_hex_algop() - use the passed algop, fill oid * Between the latter two, the "_algop" suffix signals whether the the_hash_algo is used as the implied algorithm or the caller should pass an algorithm explicitly. That is very much understandable and is a good convention. Between the former two, however, the "SHA1" vs "OID" in the names differentiate in what type of variable the result is stored. We could argue that it makes sense to use "SHA1" to mean "flat byte buffer" to honor the historical practice in the days before "struct object_id" was invented, but the natural fourth friend of the above group would take an algop and fill a flat byte buffer, and it would be strange to name it get_sha1_hex_algop(). Do we use the passed in algo, or are we limited to SHA-1 ;-)? In fact, such a function exists, albeit as a private helper function used by the implementation of these functions, and is named a lot more sensibly: get_hash_hex_algop(). Correct the misnomer of get_sha1_hex() and use "hash", instead of "sha1", as "flat byte buffer that stores binary (as opposed to hexadecimal) representation of the hash". The four (2x2) friends now become: * get_hash_hex() - use the implied the_hash_algo, fill uchar * * get_oid_hex() - use the implied the_hash_algo, fill oid * * get_hash_hex_algop() - use the passed algop, fill uchar * * get_oid_hex_algop() - use the passed algop, fill oid * As there are only two remaining calls to get_sha1_hex() in the codebase right now, the blast radious of this change is fairly small. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-25 07:11:03 +08:00
int get_hash_hex(const char *hex, unsigned char *sha1)
{
return get_hash_hex_algop(hex, sha1, the_hash_algo);
}
int get_oid_hex_algop(const char *hex, struct object_id *oid,
const struct git_hash_algo *algop)
{
int ret = get_hash_hex_algop(hex, oid->hash, algop);
if (!ret) {
oid_set_algo(oid, algop);
if (algop->rawsz != GIT_MAX_RAWSZ)
memset(oid->hash + algop->rawsz, 0,
GIT_MAX_RAWSZ - algop->rawsz);
}
return ret;
}
/*
* NOTE: This function relies on hash algorithms being in order from shortest
* length to longest length.
*/
int get_oid_hex_any(const char *hex, struct object_id *oid)
{
int i;
for (i = GIT_HASH_NALGOS - 1; i > 0; i--) {
if (!get_oid_hex_algop(hex, oid, &hash_algos[i]))
return i;
}
return GIT_HASH_UNKNOWN;
}
int get_oid_hex(const char *hex, struct object_id *oid)
{
return get_oid_hex_algop(hex, oid, the_hash_algo);
}
int parse_oid_hex_algop(const char *hex, struct object_id *oid,
const char **end,
const struct git_hash_algo *algop)
{
int ret = get_oid_hex_algop(hex, oid, algop);
if (!ret)
*end = hex + algop->hexsz;
return ret;
}
int parse_oid_hex_any(const char *hex, struct object_id *oid, const char **end)
{
int ret = get_oid_hex_any(hex, oid);
if (ret)
*end = hex + hash_algos[ret].hexsz;
return ret;
}
int parse_oid_hex(const char *hex, struct object_id *oid, const char **end)
{
return parse_oid_hex_algop(hex, oid, end, the_hash_algo);
}
char *hash_to_hex_algop_r(char *buffer, const unsigned char *hash,
const struct git_hash_algo *algop)
{
static const char hex[] = "0123456789abcdef";
char *buf = buffer;
int i;
/*
* Our struct object_id has been memset to 0, so default to printing
* using the default hash.
*/
if (algop == &hash_algos[0])
algop = the_hash_algo;
for (i = 0; i < algop->rawsz; i++) {
unsigned int val = *hash++;
*buf++ = hex[val >> 4];
*buf++ = hex[val & 0xf];
}
*buf = '\0';
return buffer;
}
char *oid_to_hex_r(char *buffer, const struct object_id *oid)
{
return hash_to_hex_algop_r(buffer, oid->hash, &hash_algos[oid->algo]);
}
char *hash_to_hex_algop(const unsigned char *hash, const struct git_hash_algo *algop)
{
static int bufno;
static char hexbuffer[4][GIT_MAX_HEXSZ + 1];
bufno = (bufno + 1) % ARRAY_SIZE(hexbuffer);
return hash_to_hex_algop_r(hexbuffer[bufno], hash, algop);
}
char *hash_to_hex(const unsigned char *hash)
{
return hash_to_hex_algop(hash, the_hash_algo);
}
char *oid_to_hex(const struct object_id *oid)
{
return hash_to_hex_algop(oid->hash, &hash_algos[oid->algo]);
}